Instant tea beverages are typically available to consumers as a canned or bottled, single-strength beverage ready for consumption or as a concentrate which is diluted with water to form a drinkable tea beverage. Tea extracts are prepared commercially by extraction of the leaves with water at elevated temperature and then separating the aqueous tea extract, usally a concentrate, from the leaves. The separated tea extract contains both soluble and insoluble tea solids and must undergo a series of additional processing steps to reduce the amount of insoluble solids. Conventional methods of removing insoluble tea solids are known as decreaming processes and utilize adjustments in process variables, such as temperature, to cause precipitation of the insoluble tea solids, followed by centrifugation, filtration or other equivalent techniques to remove precipitate complexes.
Conventional decreaming processes are described in Takino, U.S. Pat. No. 3,959,497, which relates to the use of tannase to provide a decreamed tea concentrate which provides a tea of improved astringency and color without turbidity. Takino notes that cream solids removed by conventional decreaming contain desirable tea color and astringency. Takino treats the cream solids with tannase to recover tea color and astringency. Takino discloses treatment of the tea extract either prior to or after centrifugation to remove the cream and also disclose treatment of the separated cream.
We have found that tea extracts which are de-creamed by conventional techniques will develop considerable haze when stored under refrigeration. The development of haze is relatively more rapid in a tea concentrate and is less rapid in ready-to-drink tea beverages. We have found that incubation with tannase as disclosed by Takino does not significantly reduce such refrigeration-developed haze.
It is an object to provide aqueous tea extracts, particularly aqueous tea concentrates, in which development of haze upon storing under refrigeration is reduced.
It is a further object to provide such extracts in which such haze development is significantly less than results from treatment with tannase alone.